The party bus that an 11-year-old girl fell out of is towed at Southwest First Avenue and Harrison Street.Victoria Edwards/The Oregonian

A Portland police investigation has found safety violations on a party bus involved in the tragic death of an 11-year-old in September.

Sgt. Pete Simpson, spokesman for the bureau, said the investigation into the Five Star Limousine vehicle is continuing but that substantial parts of the findings have been forwarded to the Multnomah County District Attorney's Office for possible prosecution.

"The case may be reviewed by a grand jury at some point," said Norm Frink, chief deputy district attorney. " There’s always a prospect for criminal charges."

Angie Hernandez

Angie Hernandez tumbled out of an emergency window on the bus when it careened around a corner, police said. She died at Southwest First Avenue and Harrison street, her skull crushed. The bus was full of kids on the way to a birthday party but no adults were in back.

Simpson said the driver, Martin Ray Brouwer, Jr., was not impaired.

The U.S. Department of Transportation and the Portland Police Bureau conducted separate examinations of the bus. Reports by three television stations -- KGW, KOIN and KATU -- said investigators found problems with some of the emergency exit windows. The reports quoted Officer Erik Koppang as saying that some of them were closed and couldn't be opened or were loose, allowing them to swing open under pressure. Simpson said investigators interviewed almost everyone on the bus and that no one reported pulling a red emergency release handle.

Lt. Robert King, a Portland police spokesman, told The Oregonian that Hernandez was sitting on top of the horseshoe-shaped couch in the back of the bus and didn't have any way to hold on when she fell to her death.

The general manager of Five Star Limousine, Rick Lycksell, said his thoughts were with the Hernandez family but declined to comment further.

The company had recently received a permit to operate in Portland and four of its vehicles passed an inspection. The bus that night was not permitted, said Kathleen Butler, manager of the regulatory division of the Portland Revenue Bureau. Brouwerwasn't permitted to drive the bus either.